And now, into the belly of the Beast Mode.After a competitive offseason, two chippy regular-season matchups and a long trail of verbal jousts between the 49ers and Seahawks, it comes down to an NFC Championship Game between the two this Sunday.It may not have been inevitable, but it's certainly fitting.Before this season even began, the 49ers and Seahawks were labeled my many national writers as the most heated rivals in the NFL, given their talent, history and feuding head coaches, Jim Harbaugh and Pete Carroll.After the Seahawks conquered the 49ers at CenturyLink Field in September, 29-3, and Seattle rolled off 12 wins in its first 13 games, it appeared certain that if the Niners were to return to the Super Bowl, they'd have to beat their NFC West rivals again, and in the house of horrors for opposing teams that is Century Link.The 49ers have lost their last two games in Seattle, but have now won eight straight – counting their divisional-round playoff victory over the Panthers in North Carolina this past weekend – and appear to be a much different team than the one crushed by the 'Hawks in Game 2 of this season.MORE: Seahawks Website Blocks Californians From Buying...